Routine use of warfarin is associated with clinical benefits in ischemic stroke patients with atrial fibrillation (AF), according to research published in BMJ.
When compared to patients who did not receive anticoagulant therapy, patients who received warfarin at hospital discharge had a lower incidence of major adverse cardiovascular events (MACE), less time spent in an institutional care facility, and a lower risk of all-cause mortality.
Warfarin seemed particularly beneficial for patients older than 80 years of age, women, and patients with more severe strokes.
Ying Xian, MD, PhD, of the Duke Clinical Research Institute in Durham, North Carolina, and his colleagues conducted this research, analyzing the association between warfarin treatment and longitudinal outcomes after ischemic stroke among AF patients.
The researchers evaluated 12,552 warfarin-naive AF patients who were admitted to 1487 hospitals across the US and were discharged between 2009 and 2011. Each patient had at least 1 year of follow-up after discharge.
In all, 11,039 (87.9%) were treated with warfarin at discharge. These patients were slightly younger and less likely to have a history of previous stroke or coronary artery disease than patients who did not receive warfarin.
Unadjusted results
At 2 years of follow-up, the incidence of MACE was significantly lower in patients treated with warfarin than in untreated patients—54.7% and 66.8%, respectively (P<0.001).
In addition, on average, patients who received warfarin had 86 more days alive and out of institutional care in the 2-year follow-up period than patients who did not receive warfarin (P<0.001).
The incidence of readmission due to ischemic stroke was significantly lower among warfarin-treated patients than untreated patients—7.9% and 11.8%, respectively (P<0.001)—but there was no significant difference in readmission due to hemorrhagic stroke—1.4% and 1.1%, respectively (P=0.50).
The incidence of all-cause mortality was significantly lower among warfarin-treated patients—32.4% and 50%, respectively (P<0.001).
Adjusted results
In adjusted analysis (weighting by the inverse probability of treatment and control for other discharge drugs), patients treated with warfarin at discharge had a significantly lower risk of MACE over 2 years. The adjusted hazard ratio (aHR) was 0.87.
Warfarin-treated patients were also more likely to spend more days alive and out of institutional care. The adjusted home-time difference was 47.6 days.
Patients on warfarin had a lower risk of all-cause mortality (aHR=0.72) and ischemic stroke readmission (aHR=0.63), but there was no significant difference between treated and untreated patients with regard to hemorrhagic stroke readmission (aHR=1.37).
The researchers said the benefits associated with warfarin were consistent across clinically relevant groups by age, sex, stroke severity, and history of stroke and coronary artery disease.
Patients aged 80 and older, women, and those with more severe stroke seemed to enjoy greater benefits from warfarin treatment, even though these groups were less likely to receive warfarin.
The researchers speculated that this might result from clinicians’ misperception of warfarin’s risks and benefits for these patient groups.
